Carrier WEATHERMAKER 48A2 Installation Instructions Manual

CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . .1,2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
Step 1 - Provide Unit Support . . . . . . . . . . . . . . . . . . . 2
• ROOF CURB
• ALTERNATE UNIT SUPPORT
Step 2 - Rig and Place Unit . . . . . . . . . . . . . . . . . . . . . 2
• POSITIONING
• ROOF MOUNT
Step 3 - Field Fabricate Ductwork . . . . . . . . . . . . . . . 2
Step 4 - Make Unit Duct Connections . . . . . . . . . . . 2
Step 5 - Install Flue Hood . . . . . . . . . . . . . . . . . . . . . . 17
Step 6 - Trap Condensate Drain . . . . . . . . . . . . . . . . 17
Step 7 - Install Gas Piping . . . . . . . . . . . . . . . . . . . . . 18
Step 8 - Make Electrical Connections . . . . . . . . . . 18
• POWER WIRING
• FIELD POWER SUPPLY
• FIELD CONTROL WIRING
Step 9 - Make Outdoor-Air Inlet
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
• ECONOMIZER AND FIXED OUTDOOR
AIR DAMPER
Step 10 - Position Power Exhaust/Barometric
Relief Damper Hood. . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Step 11 - Route VAV Static Pressure Sensor . . . 30
Step 12 - Install All Accessories . . . . . . . . . . . . . . . 30
Step 13 - Perform Field Modifications . . . . . . . . . . 33
BACnet Communication Option Wiring . . . . . . . . . 33

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can
be hazardous due to system pressure and electrical compo-
nents. Only trained and qualified service personnel should in-
stall, repair, or service air-conditioning equipment.
Untrained personnel can perform the basic maintenance
functions of cleaning coils and filters and replacing filters. All
other operations should be performed by trained service per-
sonnel. When working on air-conditioning equipment, observe
precautions in the literature, tags and labels attached to the unit,
and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for unbrazing operations. Have
fire extinguishers available for all brazing operations.
WARNING
Before performing service or maintenance operations on
unit, turn off main power switch to unit. Electrical shock
could cause personal injury.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480095-01
Single Package Gas Heating/Electric Cooling
Rooftop Units with ComfortLink Controls

Installation Instructions

Page
Printed in U.S.A.
48A2,A3,A4,A5020-060
and PURON ®
1. Improper installation, adjustment, alteration, service,
or maintenance can cause property damage, personal
injury, or loss of life. Refer to the User's Information
Manual provided with this unit for more details.
2. Do not store or use gasoline or other flammable va-
pors and liquids in the vicinity of this or any other
appliance.
What to do if you smell gas:
1. DO NOT try to light any appliance.
2. DO NOT touch any electrical switch, or use any
phone in your building.
3. IMMEDIATELY call your gas supplier from a neigh-
bor's phone. Follow the gas supplier's instructions.
4. If you cannot reach your gas supplier, call the fire
department.
DO NOT USE TORCH to remove any component. System
contains oil and refrigerant under pressure.
To remove a component, wear protective gloves and gog-
gles and proceed as follows:
a. Shut off electrical power to unit.
b. Recover refrigerant to relieve all pressure from sys-
tem using both high-pressure and low pressure ports.
c. Traces of vapor should be displaced with nitrogen
and the work area should be well ventilated. Refrig-
erant in contact with an open flame produces toxic
gases.
d. Cut component connection tubing with tubing cutter
and remove component from unit. Use a pan to catch
any oil that may come out of the lines and as a gage
for how much oil to add to the system.
e. Carefully unsweat remaining tubing stubs when nec-
essary. Oil can ignite when exposed to torch flame.
Failure to follow these procedures may result in personal
injury or death.
DO NOT re-use compressor oil or any oil that has been
exposed to the atmosphere. Dispose of oil per local codes
and regulations. DO NOT leave refrigerant system open to
air any longer than the actual time required to service the
equipment. Seal circuits being serviced and charge with
dry nitrogen to prevent oil contamination when timely
repairs cannot be completed. Failure to follow these proce-
dures may result in damage to equipment.
Form 48A-12SI Pg 1
WEATHERMAKER
Refrigerant (R-410A)
WARNING
WARNING
CAUTION
7-13 Replaces: 48A-10SI
®